时间周期哈密顿-雅克比方程的比较定理     

朴大雄  董心雷 《中国海洋大学学报(自然科学版)》2009,39(5)

在有界区域上研究时间周期哈密顿-雅克比方程的黏性解,将Hitoshi Ishii和Hiroyoshi Mitake关于自治哈密顿-雅克比方程的比较定理推广到适用于时间周期的哈密顿-雅克比方程的比较定理。  相似文献   

Climate Warming Mitigation from Nationally Determined Contributions     

Bo FU  Jingyi LI  Thomas GASSER  Philippe CIAIS  Shilong PIAO  Shu TAO  Guofeng SHEN  Yuqin LAI  Luchao HAN  Bengang LI 《大气科学进展》2022,39(8):1217-1228

Individual countries are requested to submit nationally determined contributions(NDCs) to alleviate global warming in the Paris Agreement. However, the global climate effects and regional contributions are not explicitly considered in the countries’ decision-making process. In this study, we evaluate the global temperature slowdown of the NDC scenario(?T =0.6°C) and attribute the global temperature slowdown to certain regions of the world with a compact earth system model.Considering reductions ...  相似文献   

Terrestrial vegetation carbon sinks in China, 1981―2000     

FANG JingYun  GUO ZhaoDi  PIAO ShiLong  CHEN AnPing 《中国科学D辑(英文版)》2007,50(9)

Using China's ground observations, e.g., forest inventory, grassland resource, agricultural statistics, climate, and satellite data, we estimate terrestrial vegetation carbon sinks for China's major biomes between 1981 and 2000. The main results are in the following: (1) Forest area and forest biomass carbon (C) stock increased from 116.5×106 ha and 4.3 Pg C (1 Pg C = 1015 g C) in the early 1980s to 142.8×106 ha and 5.9 Pg C in the early 2000s, respectively. Forest biomass carbon density increased form 36.9 Mg C/ha (1 Mg C = 106 g C) to 41.0 Mg C/ha, with an annual carbon sequestration rate of 0.075 Pg C/a. Grassland, shrub, and crop biomass sequestrate carbon at annual rates of 0.007 Pg C/a, 0.014―0.024 Pg C/a, and 0.0125―0.0143 Pg C/a, respectively. (2) The total terrestrial vegetation C sink in China is in a range of 0.096―0.106 Pg C/a between 1981 and 2000, accounting for 14.6%―16.1% of carbon dioxide (CO2) emitted by China's industry in the same period. In addition, soil carbon sink is estimated at 0.04―0.07 Pg C/a. Accordingly, carbon sequestration by China's terrestrial ecosystems (vegetation and soil) offsets 20.8%―26.8% of its industrial CO2 emission for the study period. (3) Considerable uncertainties exist in the present study, especially in the estimation of soil carbon sinks, and need further intensive investigation in the future.  相似文献   

管井井点降水的设计与施工     

乔松平  王世和  宫云成  朴立辉 《吉林地质》2006,25(3):51-55

本文着重探讨管井井点降水的计算方法,并结合工程实例分析管井降水设计和施工中需要注意的一些问题.  相似文献   

因子计量模型法在区域地球化学勘查中的应用     

师磊  朴寿成  江裕标 《世界地质》2007,26(1):40-43

因子分析结果受样品数量的影响，同一件样品的因子计量也随之发生变化，使传统因子计量方法在地球化学数据处理中的应用受到一定的限制。因子计量模型法综合了因子计量的优点和利用模型找矿的思路，通过选定的某一典型地质单元计算因子计量系数矩阵，建立因子计量模型，用模型类比未知区。该方法使因子计量图的地球化学意义更加明确，并且可节省重新处理数据的工作量。因子计量模型方法和传统因子计量方法应用于某地区1：20万水系沉积物地球化学数据处理，因子计量模型法得出的地球化学异常规律性更为明显，更好地反映了区域地质构造与异常的关联性，有利于异常的解释和评价。  相似文献   

辽宁丹东五龙与四道沟金矿床成因对比—流体包裹体证据     

郝通顺  王可勇  万多  朴星海  张晓东  黄俊鹏  纪兆家 《世界地质》2010,29(4):582-587

对产于辽宁丹东三股流花岗闪长岩体外围的五龙与四道沟大型金矿床地质、流体包裹体岩相学及测温特征进行对比研究表明,五龙与四道沟金矿床成因存在一定差异。五龙金矿床含金石英脉与四道沟金矿床早期石英脉成矿流体主要来自于三股流岩浆活动,而四道沟矿区主矿化阶段成矿流体来源可能与矿区燕山晚期中酸性脉岩活动有关。  相似文献   

西鄂尔多斯维管植物区系特征分析   总被引：3，自引：1，他引：2  

包萨如拉  赵利清  朴顺姬  张璞进 《中国沙漠》2012,32(2):428-436

 通过在西鄂尔多斯地区几年的植物标本采集以及参考前人对该地区植物名录的记载,对西鄂尔多斯地区野生维管植物种类组成、生活型、水分生态类型及植物区系地理成分进行了分析研究。结果表明:①西鄂尔多斯地区的野生维管植物共有64科、215属、433种;②植物的生活型以多年生草本为主,占52.66%,其他为乔木占0.69%、灌木占14.09%、半灌木占6.93%、一或二年生草本占24.25%、草质藤本占0.92%,类短命植物占0.46%;③植物的水分生态类型以旱生（包括强旱生、旱生和中旱生）为主,占49.42%,中生植物（包括旱中生、中生、湿中生）占47.58%,湿生植物占1.85%,水生植物仅占1.15%;④西鄂尔多斯地区植物区系地理成分组成复杂多样,在温带区系性质为主体的背景下,受欧亚草原区系、东亚森林区系、亚洲中部荒漠区系及古地中海区系的影响。  相似文献   

虎林市近40a日照时数的变化特征   总被引：1，自引：0，他引：1  

张秀艳  宋玉华  朴虎 《黑龙江气象》2009,26(3):27-28,32

对近40 a虎林市日照时数的年、季和月变化特征及与总云量的关系进行了分析.结果表明:近40 a虎林市年日照时数总体呈减少趋势,其气候变化率为每10a减少42.52 h,日照时数年际变化振幅较大,日照时数存在明显的季节差异,各季日照时数年际变化减少的趋势从大到小依次为:冬季、春季、秋季、夏季;各月的日照时数均呈减少趋势,12月减少趋势较为显著,8月减少的趋势不明显.日照时数与日照百分率的年际变化基本保持一致.  相似文献   

An Abrupt Rainfall Decrease over the Asian Inland Plateau Region around 1999 and the Possible Underlying Mechanism     

Jinling PIAO  Wen CHEN  Ke WEI  Yong LIU  Hans-F. GRAF  Joong-Bae AHN  Alexander POGORELTSEV 《大气科学进展》2017,34(4):456-468

A decadal change in summer rainfall in the Asian inland plateau(AIP) region is identified around 1999. This decadal change is characterized by an abrupt decrease in summer rainfall of about 15.7% of the climatological average amount,leading to prolonged drought in the Asian inland plateau region. Both the surface air temperature and potential evapotranspiration in the AIP show a significant increase, while the soil moisture exhibits a decrease, after the late 1990s. Furthermore,the normalized difference vegetation index shows an apparent decreasing trend during 1999–2007. Three different drought indices—the standardized precipitation index, the standardized precipitation evapotranspiration index, and the self-calibrating Palmer drought severity index—present pronounced climate anomalies during 1999–2007, indicating dramatic drought exacerbation in the region after the late 1990s. This decadal change in the summer rainfall may be attributable to a wave-like teleconnection pattern from Western Europe to Asia. A set of model sensitivity experiments suggests that the summer warming sea surface temperature in the North Atlantic could induce this teleconnection pattern over Eurasia, resulting in recent drought in the AIP region.  相似文献   

鲁科一井上白垩统沉积岩岩石磁学和天然剩磁分析:兼论利用剩磁方向恢复钻孔岩芯原始方位的可行性          下载免费PDF全文

韩非  秦华峰  季强  孙靖鹏  邓成龙  潘永信 《地球物理学报》2017,60(12):4730-4740

本文对"鲁科一井"(CCSD-LK-Ⅰ)768.9~1112.3m之间的上白垩统沉积岩样品进行了岩石磁学、磁化率各向异性(AMS)以及天然剩磁组分的研究.在此基础上,分析了利用特征剩磁(ChRM)和黏滞剩磁(VRM)方向恢复岩芯原始方位的可行性.三轴等温剩磁热退磁曲线、磁滞回线、反向场退磁曲线、一阶反转曲线等岩石磁学测量结果表明,沉积岩的主要载磁矿物为磁铁矿和赤铁矿.335块样品的AMS测量结果表明磁化率椭球主轴的最大轴K1和中间轴K2与水平面夹角较小,最小轴K3接近垂直于水平面分布,说明沉积岩保留了原始沉积磁组构特征.系统热退磁实验表明,多数样品在25~350℃和500~690℃温度段分别获得VRM和ChRM分量.利用ChRM偏角方向,并考虑构造旋转量校正,对VRM偏角方向进行恢复,Fisher统计得到DVRM=-1.3°,IVRM=59.6°,与当地现代地磁场方向(D=-6.7°,I=53.9°)基本一致.用ChRM偏角方向对磁化率主轴K1偏角方向进行校正,校正的结果为:D_(ch_K1)=349.2°,I_(ch_K1)=-0.7°.本文研究结果对于地质勘探中利用古地磁学方法恢复钻孔岩芯原始方位具有一定参考意义.  相似文献